The present invention relates to a method for the preparation of allylsilanes, which are useful as allyl transfer reagents for electrophilic reagents such as ketones, carboxylic acid chlorides, etc. More specifically, the present invention relates to a method for the preparation of beta-substituted allylsilanes.
Allylsilanes are often used with electrophilic reagents such as ketones, carboxylic acid chlorides, etc. (refer to A. Hosomi and H. Sakurai, Tetrahedron Letters).
Furthermore, in addition to the unsubstituted allylsilanes, this reaction has also been investigated and widely applied for allylsilanes variously substituted at the allyl group's alpha, beta, and gamma positions (refer to Ernest W. Colvin, Silicon in Organic Synthesis, pp. 104 to 117, Butterworths).
However, substituted allylsilanes have generally been difficult to prepare, and the preparative methods themselves vary according to the type and position of the substituent group. Among these, preparative methods for beta-substituted allylsilanes have proven to be particularly complex, and have involved lengthy campaigns comprising at least two steps. Furthermore, it has been necessary to use special starting materials.
The present inventors achieved the present invention as the result of extensive research directed at solving the problems arising with methods for the preparation of beta-substituted allylsilanes.